The ring configurations for classical two-dimensional atoms are calculated
within the Thomson model and compared with the results from `exact' numerical
simulations. The influence of the functional form of the confinement potential
and the repulsive interaction potential between the particles on the
configurations is investigated. We also give exact results on those eigenmodes
of the system whose frequency does not depend on the number of particles in the
system.Comment: 9 pages, RevTeX, 4 figure